Lighting devices with a specific spectral power distribution for application in e.g. food markets are known in the art. U.S. Pat. No. 8,132,939, for instance, describes the generation of an application-specific reddish or yellowish or greenish light, especially for applications in markets, e.g. food markets, with blue LEDs in association with color conversion using luminous materials. Similarly to the case of white-light generation, a blue LED with a wavelength of e.g. about 460 nm is encapsulated with the luminous material (luminous material with downward conversion of the blue light), to stimulate a color conversion. The luminous material converts part of the blue light from an LED chip into, for instance, red and/or yellow and/or green light. In particular, a luminous materials mixture, i.e. at least two different luminous materials, can be used for this purpose. In this way a special spectrum is represented, for presentation of goods in the food market with LEDs, a “white” light with a high red or yellow or green portion being generated with blue LEDs and luminous material(s).
Pettersen M K et al: “Oxidative stability of cream cheese stored in thermoformed trays as affected by packaging material, drawing depth and light”, International dairy journal, Elsevier Applied Science, Barking, G B, vol. 15, no. 4, 1 Apr. 2005 (2005 Apr. 1), pages 355-362 describes that the oxidative stability of cream cheese stored in thermoformed trays made of amorphous polyethylene terephthalate (A-PET)/polyethylene (PE), polystyrene (PS)/Ethylene-vinylalcohol copolymer (EVOH)/PE and Polypropylene (PP)/PE with different depth (25, 50 and 70 mm) and color (black, white and transparent) was studied by sensory evaluation and gas chromatographic analysis of volatile compounds. The polymer combination had an important effect on sensory scores of both sunlight and acidulous flavor in cream cheese stored in the dark for 2, 4 and 6 months. Cream cheese stored in trays made of A-PET/PE had higher acidulous flavor and lower content of hexanal and 2-nonanone. Only small differences were observed between PS/EVOH/PE and PP/PE despite the great diversity of oxygen transmission rates. The drawing depth of the packages had no significant effect on oxidative stability of cream cheese, irrespective of storage in the dark or under illumination. The color of the examined packaging material had a pronounced effect on photoxidative changes in cream cheese.
WO 2011/152879 describes solid state light sources, lighting devices and lamps arranged to provide emission with a warm temperature and high CRI. One embodiment of a solid state lighting device according to the present invention comprises a light emitting diode (LED) device capable of emitting light in an emission spectrum. A filter arranged so that at least some light from the LED light source passes through it, with the filter filtering at least some of one or more portions of the light source emission spectrum. The resulting light source light has a different temperature but substantially the same CRI after passing through the filter.
WO 2015/134630 describes that related to most light-emitting devices, such as LED luminaires, a filtering, beam-shaping optic that controls the spectral content of the emitted light and the shape of the emitted beam. One or more filtering agents are mixed with a non-filtering material used for making an optic and the optic is then formed into a desired shape or configuration to control the beam shape. Light waves in a subrange of the overall wavelength range emitted from the light source are shifted to control the spectral content of the emitted light. Spectral density of the emitted light for various wavelengths is controlled to achieve a desired result, such as minimizing the amount of blue light emitted from outdoor lighting devices, particularly at night. Further, the color content of light emitted is controlled, for example, to minimize damaging effects to light-sensitive objects such as food products, certain art materials, etc.
WO 2012/020081 describes an illumination arrangement having a lamp with a plurality of light sources, which emit light in each case of a different color, and a control unit for operating the light sources, wherein the control unit is configured to change the spectral composition of the light emitted with substantially unchanged color locus and/or unchanged color temperature, once a user has fixed a desired color locus and/or color temperature for the light emission.
Natthorn Intawiwat et al: “Effect of different wavelength of light on the formation of photo-oxidation in Gouda-like cheese”, International Dairy Journal, Elsevier Applied Science, Barking, G B, vol. 21, no. 8, 15 Mar. 2011 (2011 Mar. 15), pages 531-539, describes that Norvegia cheese samples were packed in air and nitrogen atmospheres and exposed to light of different colors, blue (350-560 nm), green (450-620 nm) and red (580-700 nm). After 7 days of light exposure, each cheese was sliced, from the exposure surface and down, into eight slices of 3 mm thickness. The slices were analyzed by sensory analysis and fluorescence spectroscopy, enabling studies of how photo-oxidation progressed as a function of depth of the cheese. Green light gave the most oxidation at the surface for air stored samples. Oxidized flavors at depths down to 9 mm were more intense for exposure to red and green light. Blue light degraded riboflavin in the two upper layers (0-6 mm), whereas red and green light affected hematoporphyrin, protoporphyrin IX and chlorophyll as far as 21 mm into the cheese. The results suggest that tetrapyrroles are responsible for photo-oxidation at the surface and the interior of the cheese.
Charlotte m. Andersen et al: “Wavelength Dependence of Light-Induced Lipid Oxidation and Naturally Occurring Photosensitizers in Cheese”, Journal Of Agricultural And Food Chemistry, vol. 56, no. 5, 1 Mar. 2008 (2008 Mar. 1), pages 1611-1618, describes that the Degradation of the potential photosensitizers, riboflavin, chlorophyll, and porphyrin, in Danbo cheese by monochromatic light of wavelength 366, 436, or 546 nm was studied. Three cheeses were investigated, two conventional (16% fat and 25% fat) and one “organic” (25% fat). The effect of illumination was measured by fluorescence spectroscopy and analyzed using multiway and multivariate data analysis. Riboflavin was found to degrade only by 436 nm light, whereas chlorophylls and porphyrins also were influenced by 436 and 546 nm light. The organic cheese had the largest chlorophyll content both before and after similar light exposure, and no change in chlorophyll of this cheese was observed for any of the illumination wavelengths. Upon light exposure of the cheeses, volatile compounds were formed, as analyzed by gas chromatography-mass spectrometry (GC-MS). The relative concentrations of methyl butanoate, 1-pentanol, benzaldehyde, 2-butanone, 2-heptanone, and butyl acetate were found to weakly correlate with the surface fluorescence intensity. 1-Pentanol and the ketones are secondary lipid oxidation products, consistent with a chemical coupling between photosensitizer degradation and formation of volatile lipid oxidation products.